Failed to start Grafana instance after upgrade the version from 6.6 to 7.56

Hi, I am trying to upgrade the Grafana version from 6.6.2 to 7.56 and after the upgrade, I am getting the below error

● grafana-server.service - Grafana instance
Loaded: loaded (/usr/lib/systemd/system/grafana-server.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Mon 2021-05-17 15:47:00 UTC; 2s ago
Docs: http://docs.grafana.org
Process: 10368 ExecStart=/usr/sbin/grafana-server --config=${CONF_FILE} --pidfile=${PID_FILE_DIR}/grafana-server.pid --packaging=deb cfg:default.paths.logs=${LOG_DIR} cfg:default.paths.data=${DATA_DIR}
Main PID: 10368 (code=exited, status=1/FAILURE)

grafana-server.service: Service hold-off time over, scheduling restart.
grafana-server.service: Scheduled restart job, restart counter is at 5.
Stopped Grafana instance.
grafana-server.service: Start request repeated too quickly.
grafana-server.service: Failed with result ‘exit-code’.
: Failed to start Grafana instance.
lines 1-13/13 (END)

==========================================
HERE IS THE GRAFANA LOG FILE

t=2021-05-17T10:03:28+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:04:28+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:05:29+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:06:20+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=GET path=/login/google status=302 remote_addr=220.48.145.230 time_ms=0 size=444 referer=http://grafana.sudhakar.com/login
t=2021-05-17T10:06:21+0000 lvl=info msg=“state check” logger=oauth queryState=55fbded22223bf0611230938ca9e34ca3e8e8dcf1c01b6d2e7d770668f7ac372 cookieState=55fbded22223bf0611230938ca9e34ca3e8e8dcf1c01b6d2e7d770668f7ac372
t=2021-05-17T10:06:21+0000 lvl=info msg=“Successful Login” logger=http.server User=sudhakar1
t=2021-05-17T10:06:21+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=GET path=/login/google status=302 remote_addr=220.48.145.230 time_ms=158 size=24 referer=http://grafana.sudhakar.com/
t=2021-05-17T10:06:29+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:07:18+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:08:18+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:08:53+0000 lvl=eror msg=“Metric request error” logger=context userId=1 orgId=1 uname=sudhakar1 error=“dbname is empty”
t=2021-05-17T10:08:53+0000 lvl=eror msg=“Request Completed” logger=context userId=1 orgId=1 uname=sudhakar1 method=POST path=/api/db/query status=500 remote_addr=220.48.230.230 time_ms=0 size=34 referer=http://grafana.sudhakar.com/datasources/edit/5/
t=2021-05-17T10:09:18+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:10:18+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:11:18+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:12:18+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:13:18+0000 lvl=info msg=“Request Completed” logger=context userId=0 orgId=0 uname= method=POST path=/tags/tagMultiSeries status=404 remote_addr=127.0.0.1 time_ms=1 size=26123 referer=
t=2021-05-17T10:13:55+0000 lvl=info msg=“Shutdown started” logger=server reason=“System signal: terminated”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped UsageStatsService” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped PluginManager” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped CleanUpService” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped RemoteCache” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped UserAuthTokenService” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped Stream Manager”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped NotificationService” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped InternalMetricsService” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped provisioningServiceImpl” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped BackendPluginManager” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=info msg=“Stopped AlertEngine” logger=server reason=“context canceled”
t=2021-05-17T10:13:55+0000 lvl=eror msg=“Server shutdown” logger=server reason=nil
t=2021-05-17T10:13:56+0000 lvl=info msg=“Starting Grafana” logger=server version=7.5.6 commit=5fdad5bfe4 branch=HEAD compiled=2021-05-11T12:02:27+0000
t=2021-05-17T10:13:56+0000 lvl=info msg=“Config loaded from” logger=settings file=/usr/share/grafana/conf/defaults.ini
t=2021-05-17T10:13:56+0000 lvl=info msg=“Config loaded from” logger=settings file=/etc/grafana/grafana.ini
t=2021-05-17T10:13:56+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.data=/var/lib/grafana”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.logs=/var/log/grafana”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.plugins=/var/lib/grafana/plugins”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.provisioning=/etc/grafana/provisioning”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Path Home” logger=settings path=/usr/share/grafana
t=2021-05-17T10:13:56+0000 lvl=info msg=“Path Data” logger=settings path=/var/lib/grafana
t=2021-05-17T10:13:56+0000 lvl=info msg=“Path Logs” logger=settings path=/var/log/grafana
t=2021-05-17T10:13:56+0000 lvl=info msg=“Path Plugins” logger=settings path=/var/lib/grafana/plugins
t=2021-05-17T10:13:56+0000 lvl=info msg=“Path Provisioning” logger=settings path=/etc/grafana/provisioning
t=2021-05-17T10:13:56+0000 lvl=info msg=“App mode production” logger=settings
t=2021-05-17T10:13:56+0000 lvl=info msg=“Writing PID file” logger=server path=/var/run/grafana/grafana-server.pid pid=10105
t=2021-05-17T10:13:56+0000 lvl=info msg=“Connecting to DB” logger=sqlstore dbtype=sqlite3
t=2021-05-17T10:13:56+0000 lvl=info msg=“Starting DB migrations” logger=migrator
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add index user.login/user.email”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop index IDX_temp_user_email - v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop index IDX_temp_user_org_id - v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop index IDX_temp_user_code - v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop index IDX_temp_user_status - v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Rename table temp_user to temp_user_tmp_qwerty - v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“create temp_user v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“create index IDX_temp_user_email - v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“create index IDX_temp_user_org_id - v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“create index IDX_temp_user_code - v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“create index IDX_temp_user_status - v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“copy temp_user v1 to v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop temp_user_tmp_qwerty”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Set created for temp users that will otherwise prematurely expire”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add index for dashboard_title”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“delete tags for deleted dashboards”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“delete stars for deleted dashboards”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add uid column”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Update uid value”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add unique index datasource_org_id_uid”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“add unique index datasource_org_id_is_default”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add encrypted dashboard json column”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Change dashboard_encrypted column to MEDIUMBLOB”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop index UQE_alert_rule_tag_alert_id_tag_id - v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Rename table alert_rule_tag to alert_rule_tag_v1 - v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Create alert_rule_tag table v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“create index UQE_alert_rule_tag_alert_id_tag_id - Add unique index alert_rule_tag.alert_id_tag_id V2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“copy alert_rule_tag v1 to v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop table alert_rule_tag_v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add column secure_settings in alert_notification”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“alter alert.settings to mediumtext”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add non-unique index alert_notification_state_alert_id”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add non-unique index alert_rule_tag_alert_id”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop index UQE_annotation_tag_annotation_id_tag_id - v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Rename table annotation_tag to annotation_tag_v2 - v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Create annotation_tag table v3”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“create index UQE_annotation_tag_annotation_id_tag_id - Add unique index annotation_tag.annotation_id_tag_id V3”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“copy annotation_tag v2 to v3”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“drop table annotation_tag_v2”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add index for alert_id on annotation table”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“add index team_member.team_id”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“delete acl rules for deleted dashboards and folders”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“add index user_auth_token.user_id”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“Add revoked_at to the user auth token”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“create short_url table v1”
t=2021-05-17T10:13:56+0000 lvl=info msg=“Executing migration” logger=migrator id=“add index short_url.org_id-uid”
t=2021-05-17T10:13:56+0000 lvl=info msg=“migrations completed” logger=migrator performed=46 skipped=233 duration=404.482982ms
t=2021-05-17T10:13:56+0000 lvl=info msg=“Starting plugin search” logger=plugins
t=2021-05-17T10:13:56+0000 lvl=info msg=“Registering plugin” logger=plugins id=input
t=2021-05-17T10:13:56+0000 lvl=info msg=“HTTP Server Listen” logger=http.server address=[::]:3000 protocol=http subUrl= socket=
t=2021-05-17T10:15:55+0000 lvl=info msg=“Shutdown started” logger=server reason=“System signal: terminated”
t=2021-05-17T10:15:55+0000 lvl=info msg=“Starting Grafana” logger=server version=7.5.6 commit=5fdad5bfe4 branch=HEAD compiled=2021-05-11T12:02:27+0000
t=2021-05-17T10:15:55+0000 lvl=info msg=“Config loaded from” logger=settings file=/usr/share/grafana/conf/defaults.ini
t=2021-05-17T10:15:55+0000 lvl=info msg=“Config loaded from” logger=settings file=/etc/grafana/grafana.ini
t=2021-05-17T10:15:55+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.data=/var/lib/grafana”
t=2021-05-17T10:15:55+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.logs=/var/log/grafana”
t=2021-05-17T10:15:55+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.plugins=/var/lib/grafana/plugins”
t=2021-05-17T10:15:55+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.provisioning=/etc/grafana/provisioning”
t=2021-05-17T10:15:55+0000 lvl=info msg=“Path Home” logger=settings path=/usr/share/grafana
t=2021-05-17T10:15:55+0000 lvl=info msg=“Path Data” logger=settings path=/var/lib/grafana
t=2021-05-17T10:15:55+0000 lvl=info msg=“Path Logs” logger=settings path=/var/log/grafana
t=2021-05-17T10:15:55+0000 lvl=info msg=“Path Plugins” logger=settings path=/var/lib/grafana/plugins
t=2021-05-17T10:15:55+0000 lvl=info msg=“Path Provisioning” logger=settings path=/etc/grafana/provisioning
t=2021-05-17T10:15:55+0000 lvl=info msg=“App mode production” logger=settings
t=2021-05-17T10:15:55+0000 lvl=info msg=“Writing PID file” logger=server path=/var/run/grafana/grafana-server.pid pid=19848
t=2021-05-17T10:15:55+0000 lvl=info msg=“Connecting to DB” logger=sqlstore dbtype=sqlite3
t=2021-05-17T10:15:55+0000 lvl=info msg=“Starting DB migrations” logger=migrator
t=2021-05-17T10:15:55+0000 lvl=info msg=“migrations completed” logger=migrator performed=0 skipped=279 duration=998.775µs
t=2021-05-17T10:15:55+0000 lvl=info msg=“Starting plugin search” logger=plugins
t=2021-05-17T10:15:56+0000 lvl=info msg=“Registering plugin” logger=plugins id=input
t=2021-05-17T10:15:56+0000 lvl=info msg=“HTTP Server Listen” logger=http.server address=[::]:3000 protocol=http subUrl= socket=
t=2021-05-17T10:19:00+0000 lvl=info msg=“Shutdown started” logger=server reason=“System signal: terminated”
t=2021-05-17T10:19:00+0000 lvl=info msg=“Starting Grafana” logger=server version=7.5.6 commit=5fdad5bfe4 branch=HEAD compiled=2021-05-11T12:02:27+0000
t=2021-05-17T10:19:00+0000 lvl=info msg=“Config loaded from” logger=settings file=/usr/share/grafana/conf/defaults.ini
t=2021-05-17T10:19:00+0000 lvl=info msg=“Config loaded from” logger=settings file=/etc/grafana/grafana.ini
t=2021-05-17T10:19:00+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.data=/var/lib/grafana”
t=2021-05-17T10:19:00+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.logs=/var/log/grafana”
t=2021-05-17T10:19:00+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.plugins=/var/lib/grafana/plugins”
t=2021-05-17T10:19:00+0000 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.provisioning=/etc/grafana/provisioning”
t=2021-05-17T10:19:00+0000 lvl=info msg=“Path Home” logger=settings path=/usr/share/grafana
t=2021-05-17T10:19:00+0000 lvl=info msg=“Path Data” logger=settings path=/var/lib/grafana
t=2021-05-17T10:19:00+0000 lvl=info msg=“Path Logs” logger=settings path=/var/log/grafana
t=2021-05-17T10:19:00+0000 lvl=info msg=“Path Plugins” logger=settings path=/var/lib/grafana/plugins
t=2021-05-17T10:19:00+0000 lvl=info msg=“Path Provisioning” logger=settings path=/etc/grafana/provisioning
t=2021-05-17T10:19:00+0000 lvl=info msg=“App mode production” logger=settings
t=2021-05-17T10:19:00+0000 lvl=info msg=“Writing PID file” logger=server path=/var/run/grafana/grafana-server.pid pid=20068
t=2021-05-17T10:19:00+0000 lvl=info msg=“Connecting to DB” logger=sqlstore dbtype=sqlite3
t=2021-05-17T10:19:00+0000 lvl=info msg=“Starting DB migrations” logger=migrator
t=2021-05-17T10:19:00+0000 lvl=info msg=“migrations completed” logger=migrator performed=0 skipped=279 duration=1.053252ms
t=2021-05-17T10:19:00+0000 lvl=info msg=“Starting plugin search” logger=plugins
t=2021-05-17T10:19:00+0000 lvl=info msg=“Registering plugin” logger=plugins id=input
t=2021-05-17T10:19:00+0000 lvl=info msg=“HTTP Server Listen” logger=http.server address=[::]:3000 protocol=http subUrl= socket=
t=2021-05-17T10:45:36+0000 lvl=info msg=“Shutdown started” logger=server reason=“System signal: terminated”

perhaps this is useful?